GENERAL

Acceptance of materials relating to structural steel
fabrication is based on producer or supplier certifications, or by acceptable
test results of samples obtained by a representative of the Iowa DOT. Sample
arrangements and locations will be determined after copies of fabricator
purchase orders for all materials required (except structural steel) have been
received by the Iowa DOT Office of Materials.

All products of iron, steel and/or coatings
shall be
of domestic origin, melted and manufactured
in the USA. The fabricator shall certify by letter to the Iowa DOT that these
materials are of domestic origin.

Listed below are the inspection requirements
and the basis of acceptance of various materials used in structural steel
fabrication. For acceptance procedures of items not listed below, contact the
Iowa DOT Office of Materials (Structural Materials Engineer).

A. Structural
Steel

1. Grades of Steel

ASTM
A709/A709M

Grade US (SI)

Yield Strength,

ksi (MPa)

Grade Non-fracture

Critical-Charpy

Grade Fracture

Critical Charpy

36 (250)

36 (250)

36T (250T)

36F (250F)

50 (345)

50 (345)

50T (345T)

50F (345F)

50S (345S)

50 (345)

50ST (345 ST)

50SF (345 SF)

50W (345W)

50 (345)

50WT (345 WT)

50WF (345 WF)

HPS 50W (HPS 345W)

50 (345)

HPS 50 WT (HPS345 WT)

HPS 50 WF (HPS 345 WF)

HPS 70W (HPS 485W)

70 (485)

HPS 70 WT (HPS 485 WT)

HPS 70 WF (HPS 485 WF)

100 (690)

100 (690)

100T (690T)

100F (690F)

100W (690W)

100 (690)

100WT (690 WT)

100 WF (690 WF)

HPS 100W (HPS 690W)

100 (690)

HPS 100 WT (HPS 690 WT)

HPS 100 WF (HPS 690 WF)

W
signifies weathering.

Other steels may be used as required by the
contract documents or
as approved by the
engineer.

Structural
steel will be accepted on the basis of Mill Test Certifications and physical
inspection at the fabrication site. Mill Test Reports need not be notarized,
but must bear the name and signature of a responsible representative of the
company. Mill Test Certifications shall clearly show the origin of the
material.

The shop
inspector shall be given Mill Test Certifications in triplicate at the earliest
possible date prior to the fit-up stage of bridge fabrication. Upon receipt of
the Mill Test Certifications, the inspector will check the physical and
chemical test results to determine compliance with the designated grade of
steel and the Buy American requirements. Charpy test results shall be actual
figures of individual test. When compliance has been determined, the inspector
will date and initial the certifications.

Certification
of compliance from a steel supplier in lieu of a Mill Test Certification is
acceptable providing actual test values are shown and a responsible
representative of the supplier signs the certification.

4. Physical Inspection
of Structural Steel by the Inspector at the Fabrication Plant

Thickness and width
of structural steel used as main members except those listed above shall be
measured to the nearest 1/16-inch (1.6 mm).

b. Determining
Mass Compliance of Rolled Beams

Shop inspection
to determine the mass of rolled beams shall be by the following method:

1)Measure the flange
thickness and record the average flange thickness

2)Measure the web
thickness and record the measurement

3)Add the theoretical
thickness of one flange and the web

4)Add the actual
(average) measured thickness of the web and the actual (average) thickness of
the flange measurements.

5)Subtract the
"actual measured" total from the theoretical total.

6)Divide this
difference by the theoretical total and multiply by 100 to secure percent
underweight (the specified mass tolerance is minus 2.5 percent).

The
Structural Materials Engineer shall be contacted when the formula indicates a
beam is outside of tolerance. Location of the beam in the structure will be a
factor in determining status of beam, which is outside of allowable tolerance.
Actual weighing of beam may be required.

c. Mill
Rolling or Handling Defects

Laminations - edges,
longitudinal, and transfers. (See AWS D1.5 Specifications for limitations
and method of repair.) Contact the Structural Materials Engineer for the
final disposition of laminations.

Typical
Swedge Anchor Bolt

C. Shear
Studs (AWS D1.5 Stud Welding)(IM 453.10)

1. Acceptance

Acceptance of shear
studs is based on Mill Test Certification showing actual results of tests
conducted not more than six months prior to the date of delivery of the studs.
Approved sources are listed in IM 453.10, Appendix A.

Approval of bronze
bearing plates is based on the correlation of test bars submitted to the Iowa
DOT by the supplier and the test results of the manufactured plates sampled at
the fabricator's plant by the Iowa DOT inspector. One plate shall be submitted
for testing representing each heat from which castings were poured. A
manufacturer's certification showing actual test results in also required.

Inspection of
dimensions, inserts and finish shall be conducted on the samples submitted to
the Iowa DOT.

Cold drawn steel for
pins and rollers is accepted by Mill Test Certification providing that in
addition to the chemical analysis, either the hardness or tensile strength is
recorded. If this information is not shown on the certification, a test sample
is required.

Approval of bolts,
nuts and washers is based on test results of samples selected and submitted to
the Iowa DOT Laboratory by a representative of the DOT. High strength bolts,
nuts and washers shall be marked as prescribed in ASTM A-325. The sampling
frequency shall be as listed in IM 453.06B. The sampling frequency for ASTM
A-307 bolts, nuts and washers of each diameter and length represented) shall be
as follows:

Acceptance is based
on a list of approved brands for which satisfactory test reports have been made
within the last year by the manufacturer. Random filler metal tests may be
required to substantiate manufacturer test results. The Central Materials
Office issues a list of approved brands of electrodes every six months.

An electromagnetic
thickness gauge either at the fabricating plant or at the job site shall
inspect galvanizing thickness. Galvanized hardware shall be sampled and
submitted to the Iowa DOT Central Laboratory for testing.